Disk-drill bit



Nov. 27|, 192s.

W. C. BAILEY DISK DRILL BIT Filed March l17, 1924 Patented Nov. 27,1928.

' UNTTED STATES WALTER C. BAILEY, OF NORWALK, CALIFORNIA.

msx-DRILL Brr.

Application filed March 17, 1924. Serial No. 699,805.

This invention relates to disk drill bits such as are used for thedrilling of wells; and it relates particularly to improvements whichwill overcome many of the disadvantages of the present types of bit.

It is an object of the present invention to provide a rotary disk bithaving a single depending disk-supporting leg provided with independentdisk-supporting pins, each extending entirely through said leg in aseparate pin-receiving opening, whereby each pin has a supportingbearing throughout the entire thickness of said leg so that thedimensions of said leg may be restricted to contribute to a structure ofrelatively thin crosssectional character which will permit a positioningof the opposed disks in close relationship on opposite sides of thevertical axis of the bit, and which will function as an agitating meansto maintain the fluid at the bottom of a well bore in a state of violentagitation to promote a quick removal of the drilling detritus andprevent mudding-up of the bit.

above character in which the disk-supporting pins may be of relativelylarge size, and in which the disks are positioned to engagethrust-receiving surfaces extending to quite near their cuttingperipheries.

Another object is to provide an arrangement of the above character inwhich the pins and disks are arranged so that a removal or loss of adisk in a well bore will have no effect upon the remaining disk and itsbearing.

A further object is' to provide a disk bit of the above type in whichthe disks are disposed in advance of said leg relative to the rotationof the bit and positioned so that the cutting is performed by thefollowing or trailing edges of the cutters.

Another object is to provide a cutting disk formed to turn cuttingdetritus away from its forward face.

Another object is to provide a disk bit of the above type in which thewear-receiving parts are both rugged and easily removable, and whichwill be economical t0 manufacture, to operate, and to maintain inoperative condition.

Further objects and advantages will be made evident hereinafter.

Referring to the drawings, which are for illustrative purposes only,

A further object is to provide a bit of the i Fig. l is a side elevationof a disk bit which embodies various features of my invention.

Fig 2 is a horizontal section taken as ndicated by the line 2 2 of Fig.l. Figs. 3 and 4L are diagrammatic vieW's, illustrating the manner inwhich the disks are rotated.

Rotary diskbits are generally designed to function upon one of twodistinctly different theories of cutter action. In one type, the disksare disposed so that the cutting is performed by the forward or leadingportions of the peripheries of the cutters, and in the other they aredisposed so that the cutting is performed by the rearward or followingportions of the peripheries of the cutters. In the first the rotation ofthe bit tends to revolve the individual disks so that the leadingportions of their cutting edges travel downwardly while the friction Onthe side wall of the bore, during descent of the bit, tends to revolvesaid disks. in a reverse direction. Thus there are two opposedforceswhich, when equalized, will maintain the disks against rotation and socause them to wear Hat on one side. In the second type above mentionedthese two forces are exerted in coincident directions, thus insuring aconstant revolving of the disks such. as is most desirable in disk bits.

The severe strains to which the disks are subjected make it exceedinglydesirable that their bearing pins be of relatively large d i-y ameterand the tilting strains occasioned by the angular disposition of thedisks renders it desirable to support the disks, so that the thrust betowards the support instead of away therefrom, this tilting influencealso rendering it advantageous that said support present as large althrust-receiving surface as possible so as to engage the disks as neartheir cutting peripheries as possible without interference with thecutting action.

In certain types of disk bits the disks are carried by respectiveindependent legs depending from the bit body, each disk being positionedadjacent the inner side of its supporting leg. The forging of such abody is very expensive. In another type, each disk is positioned betweena central depending leg and an outer depending leg with its bearing pinsupported at opposite ends in both legs. Bits of this character are soexpensive that they are not generally used in the oil industry.excepting when equipped with toothed rollers suitable for boring inhard rock, in place of plain disks. Such 4bits are very liable to mud-updue to the obstruc tion presented to a free removal of the drillingdetritus by the supporting legs. In another type of disk bit havin asingle supporting depending leg, the disk-supporting pins are formedintegral with the body. A body of this type is expensive to manufactureand is an economic failure for the reason that if one of the pinsfracture or its threads become damaged, the entire body must bediscarded. It has heretofore been proposed to provide a singlesupporting leg carrying removable and replaceable bearing pins forcutting disks, but these pins are ordinarily offset so slightly as toprevent each from extending morev than half way through the supportingleg, or they are intermeshed and dependent upon each other for securancein said leg; in either case the leg must be of considerable width toproperly support both pins. Such a construction is not desirable as itprevents the opposed disks from being positioned as near the axis of bitrotation as is desired, and for the further reason that it presents abulky structure which is quite likely to mud-up, it being stated thatthere is a decided advantage in providing a bit relatively thin in onetransverse direction so that the bit will func-tion in the manner `of anagitator to keep the circulation fluid in the bottom of the well bore ina state of violent agitation.

The desirable features above enumerated are present in the disk bitherein disclosed and the structure is particularly designed to eliminatethe disadvantages of the several types of disk bits heretofore produced.

The drill bit shown in the drawings comprises a body 11 having acentrally disposed leg 12 extending therefrom and optionally arrangedcoaxially of the body 11. A usual threaded pin 13 may be provided at theupper end o-f the body 11, for securing said body to a drill string.T'he leg 12 is preferably of a substantially rectangular cross section,as shown; andy it may be arranged symmetrically with reference to acentral plane- -b, including the longer horizontal diameter of said leg.Eccentrically located holes 15 may be provided in the leg 12, andextending at right angles to the plane -b, through which securing pins16 may extend to provide laterally offset supports for cutting disks.The pins 16 may comprise cylindrical portions 17, adapted to lit in theholes 15, and they may have hexagonal or other non-circular heads 18which are shown as resting in countersinks or recesses 19, `thisconstruction being intended to make the pins non-rotatable. The pins 16may protrude in opposite direcu tions, as shown, so that their threadedportions 20 are on the opposite sides of the leg 12.

To provide extensive and replaceable bearing surfaces, rugged andhardened bushings 22 may be threaded o-nto the extending portions 20 ofthe substantially parallel horizontal spindles or pins 16, in such amanner that they may clamp said pins 16 rigidly in place; and they mayserve to secure removable thrust washers or wear plates 24, which arepreferably so broad as to extend to the edges of the leg 12. Eachbushing 22 may be internally threaded at 26, and each may have ahardened bearing surface 27, on which a rotary disk cutter 28 may berotatably mounted. The bushings 22 may be locked in 'place by means suchas the lock nuts 30, which may be threaded on the reduced ends 31 of thepins 16 and which may fit in countersinks or recesses 32 of saidbushings.

The disks 28 may provide peripheral cut-l ting edges 33 disposed asshown in Fig. 2. Each -disk may be externally rounded t-o provideclearance behind a cutting edge, the front surface of which may beformed by a concavity comprising an outer conical area which may be ofsuch form that, when a pair of disks are mounted in the offsetrelationship shown, a line connecting the extreme outer points of a pairof disks will lie in the conical surfaces o-f both disks. At the extremepoints referred to, the conical surfaces will evidently lie at an anglenot exceeding degrees tothe Wall of the hole, or on radii of the bit,this relationship being favorable to effective. cutting without unduewear.

As mentioned, it is desirable to provide a bit in which the disks willrotate continually in one direction regardless of the hardness of therock encountered, and, in ord-er to accomplish this, it is necessarythat friction-on the bottom and at the sides of each disk tend to rotateit in the same one direction. As shown in Fig. 3, when the bit isprogressing downwardly, as indicated by the arrow 40, the friction onthesides of the disks, caused by this contact `with the sides of thehole, tends to rotate the disks as indicated by the arrows 41. Duringits advance, the bit is intended to be rotated in the direction of thearrow 43, in Fig. 4. The cutting faces of the disks 28 are arranged sothat they extend' in planes as indicated by the line c-c, which pass infront of the central leg-bisecting' diametric plane b-b, extendingthrough. the vertical axis of rotation -a and including the longerhorizontal diameter of the leg 12, from which the pins 15 extendperpendicu- `larly. Taking, for illustration, the points 44, which arethe lowermost points on the disks, these points being in the verticalplanes 0-0 of the disks, the locus of all points 44 may be representedby the line 45. An arrou7 46 may then represent the opposition of therock, tending to rotate the lower portions of the disks in the directionindicated by the arrow 47, and it will be seen that this compo nent iseiective in the same direction as the arrow 41, representing therotative tendency due to lateral engagement incidental to descent.Similar results may be accomplished by placing the cutting edge in otherplanes parallel With and in front of the plane b-b (passing through thecenter ot the head and parallel With the cutting faces) and Water orslush ducts D may be arranged as desired.

When the bit is being rotated, the cutters Contact With the Wear orthrust plates 24 at points affording adequate support near the cuttingedges 33. Instead of interposing additional Wear plates between theshoulders or flanges 51 of the bushings 22 and the correspending surface52 of a disk, I may shorten and recut or merely replace my Wornbushings; and it is an especial merit of the construction herein shownand described that, referring, for example, to the relationships betweenthe points X, Y and Z of Fig. 2, and regarding X as a point at Whichpressure is applied and-Y as the fulcrum of a lever, the arm YZ is verylong in comparison with the arm XY. Most ot' the Wear may therefore comeon `the Wear plates 24.' The threads on pins 16 may be such that thenormal rotation of the disks shall tend to tighten the bushings thereof(suitable clearance being provided to permit free rotation of the disks28) and, to assure a locking action, the lock nuts 8() may be providedWith threads of an opposite or different pitch. It Will be understoodthat, although my bushings, Wear plates and disks are intended'to beconveniently replaceable, any or all of these parts may be initiallyformed Wholly or partly of an exceptionallyl hard material, such as atool or special steel; and although I consider it desirable to supportthe disks 28, when lateral adjustment is not required, from a singleleg, not all of the advantages of my invention are dependent upon thisor any specific mode of support. The line X-X may advant-ageousv ly forman angle of about 22 degrees With the line b-b, and the fronts of mydisks may advantageously be made harder than their backs.

Although, I have herein described, in detail, but one speeilicembodiment of my invention, it should be understood that variousfeatures thereof may be separately or collectively embodied in otherconstructions Within the scope of this invention.

I claim as my invention:

l. In a rotary disk drill bit, the combination of: a body rotatableabout its vertical axis and having a cent-ral depending leg; tworotatable cuttingl disks supported entirely by and mounted on oppositesides of said leg and transversely offset relative to each other inopposite directions from the vertical axis of the body, each disk beingin advance of said leg in relation to the cutting rotation thereof andan independent supporting bearing pin for each disk, each bearing pinextending entirely through said leg.

2. In a rotary disk drill bit, the combination of: a body rotatableabout its vertical A axis and having a central depending leg; two

rotatable cutting disks supported entirely by and mounted on oppositesides of said leg and transversely odset relative to each other inopposite directions romthe vertical axis of the body, each disk being inadvance of said leg in relation to the cutting rotation thereof; and anindependent supporting bearing pin for each disk, said bearing pinsextending entirely through said leg and being horizontally parallel toposition the disks in relative parallel vertical planes.

3.' In a rotarydisk drill bit, the combinat-ion ot' a central supportingleg adapted to be rotated upon a vertical axis; olset disks entirelysupported by said leg .and mounted thereon in advance of the majorvertical axial plane of said leg; and mounting means for each of saiddisks including an independent removable pin rigidly secured in saidleg.

et. In a rotary disk drill bit, the combination of: a central supportingleg adapted to be rotated upon a vertical axis; ott'set disks entirelysupported by said leg and mounted thereon in advance of the majorvertical axial plane of said leg; and mounting means for` each of saiddisks including an independent removable pin rigidly secured in said legand having intermeshing engagement therewith to prevent rotation of saidpin.

5. In a rotary disk drill bit, the combination of: a body rotatableabout its vertical axis and having a central depending leg; tworotatable cutting disks supported entirely by and mounted on oppositesides of said leg and transversely oli'set relative to each other inopposite directions from the vertical axis of the body, each disk beingin advance of said leg in relation to the cutting rotation thereof; yandmounting means for said disks'including independent relatively spacedremovable pins, each extending entirely through said leg and restrainedagainst rotation by intermeshing engagement with said leg.

6. Ina rotary disk drill bit, the combination of: a body rotatable aboutits vertical axis and having a central depending leg provided With twohorizontally spaced nonintersectingtransverse openings extendingtherethrough; a bearing pin removably secured in each opening andrestrained against rotation, each pin being inserted from one side ofsaid leg with its free end projecting beyond the opposite side ot theleg; and a cutting disk rotatably lnounted upon the free end of eachpin.

7. In a rotary disk drill bit, the combination of: a body rotatableabout its vertical axis and having a central depending leg; tworotatable. cutting disks entirely supported by and mounted on oppositesides of said leg and in relative offset transverse rela-tion onopposite sides of the vertical axis of the body, each disk being inadvance of said leg in relation to the cutting rotation thereof; and anindependent supporting bearing for each disk, said bearings eachcomprising an independent pin extendingentirely through said leg and abushing screw-threaded thereon and and clamping said pin in the leg.

8. In a rotary disk drill bit, the combination of: a body rotatableabout its .vertical axis and having a central depending leg; tworotatable cutting disks entirely supported by and mounted on oppositesides of said leg and in relative offset transverse relation on oppositesides of thevertical axis of the body, each disk being in advance ofsaid leg in relation to the cutting rotation thereof and an independentsupporting bearing for each disk, said bearings each comprising anindependentl pin ext-ending entirely through said leg, a bushingscrew-threaded thereon and clamping said pin in the leg, and a lock nutscrewthreaded on the pin and engaging the bushlng.

9. In .a rotary disk drill bit, the combina- 4tion. of: a body rotatableabout its vertical axis and having a depending leg provided with twotransversely adjacent relatively parallel nonintersectin g openingsbearing pins in said openings, each pin extending outwardly from saidleg in a direction opposite to that of the adjacent pin; securing meansengaging the projecting end of each pin and overlapping the head of theadjacent pin; and a cut-ting disk journaled on the projecting end ofeach pin.

10. In a rotary disk drill bit, the combination of: a body rotatableabout its vertical axis and having a depending leg provided with twotransversely adjacent relatively parallel nonintersecting openings;bearing pins in said openings, each pin extending outwardly from saidleg in a direction opposite to that of the adjacent pin; wear platesengaging the projecting end of each pin and overlapping the head of theadjacent pin; bushings screw-threaded on the pins and clamping the pinsand Wear plates in place; and a cutting disk journaled on each bushing.

11. In a rotary disk drill bit, the comb-ina.- tion of: a body rotatableabout a vertical axis and having a relatively thin central depend ingleg provided with two nonintersecting openings spaced horizontally fromeach other in opposite directions from said vertical axis; two disksupporting pins disposed in said openings to project respectively fromopposite major vertical faces of said leg; two cutting disks; and meansfor rotatably mounting a disk upon each of said pins, where these pinsproject from said major faces.

12. In a rotary disk drill bit, the combination of: a body rotatableabo-ut a vertical axis and having a relatively thin central dependingleg provided with two nonintersecting openings spaced horizontally fromeach other in opposite directions from said vertical axis, said openingsextending entirely through said leg; two disk supporting pins disposedin said openings to project respectively from opposite major verticalfaces of said leg, said disk supporting pins having head portions shapedto prevent said pins being passed entirely through said openings; twocutting disks; andrneans for rotatably mounting a disk upon each of saidpins, where these pins project from said major faces, said meanspreventing movement of said pins from said openings.

In testimony whereof, I have hereunto set my hand at Los Angeles,California, this 6th day of March, 1924.

WALTER c. BAILEY.

so y

